double quote enum key if it contains special characters (#648)

src/generator.ts

@@ -329,13 +329,20 @@ function generateComment(comment?: string, deprecated?: boolean): string {
 }
 
 function generateStandaloneEnum(ast: TEnum, options: Options): string {
+  const containsSpecialCharacters = (key: string): boolean => /[^a-zA-Z0-9_]/.test(key)
+
   return (
     (hasComment(ast) ? generateComment(ast.comment, ast.deprecated) + '\n' : '') +
     'export ' +
     (options.enableConstEnums ? 'const ' : '') +
     `enum ${toSafeString(ast.standaloneName)} {` +
     '\n' +
-    ast.params.map(({ast, keyName}) => keyName + ' = ' + generateType(ast, options)).join(',\n') +
+    ast.params
+      .map(
+        ({ast, keyName}) =>
+          (containsSpecialCharacters(keyName) ? `"${keyName}"` : keyName) + ' = ' + generateType(ast, options),
+      )
+      .join(',\n') +
     '\n' +
     '}'
   )

test/__snapshots__/test/test.ts.md

@@ -1054,6 +1054,29 @@ Generated by [AVA](https://avajs.dev).
     }␊
     `
 
+## enum.6.js
+
+> Expected output to match snapshot for e2e test: enum.6.js
+
+    `/* eslint-disable */␊
+    /**␊
+     * This file was automatically generated by json-schema-to-typescript.␊
+     * DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,␊
+     * and run json-schema-to-typescript to regenerate this file.␊
+     */␊
+    ␊
+    export interface Enum {␊
+      specialStringEnum: SpecialStringEnum;␊
+    }␊
+    ␊
+    export const enum SpecialStringEnum {␊
+      "text/plain" = "text/plain",␊
+      a = "a",␊
+      "b-c" = "b-c",␊
+      "d.e" = "d.e"␊
+    }␊
+    `
+
 ## enum.js
 
 > Expected output to match snapshot for e2e test: enum.js

test/e2e/enum.6.ts

@@ -0,0 +1,16 @@
+export const input = {
+  title: 'Enum',
+  type: 'object',
+  properties: {
+    specialStringEnum: {
+      type: 'string',
+      enum: ['text/plain', 'a', 'b-c', 'd.e'],
+    },
+  },
+  required: ['specialStringEnum'],
+  additionalProperties: false,
+}
+
+export const options = {
+  inferStringEnumKeysFromValues: true,
+}